1. Field of the Invention
The present invention relates to a printing device for printing a text including a desirable series of characters on a tape, and more specifically to a novel printing device having a function of printing the text in a plurality of lines on a tape. The invention also pertains to an improved printing device where attribute data such as character sizes are simply specified for plural-line printing. The invention further relates to a printing image display unit, incorporated in a printing device for printing a text on a tape medium, for displaying a printing image of the text on a liquid-crystal display prior to actual printing operation.
2. Description of the Related Art
Tape printing devices generally known are used for printing a desirable series of characters on a surface of an adhesive tape having an adhesive rear face. With such a tape printing device, a desirable title or name is printed on a label (cut piece of a tape) through simple operation. These labels with an adhesive are applied in both domestic and business fields, for example, on the spine of business files or the back of video tapes.
The tape printing device is used for printing one or plural rows of input characters including letters and symbols (hereinafter referred to as text) on a tape and cutting the tape at a desirable position to a label of a predetermined length. Improved tape printing devices allowing plural-line printing have been proposed to meet the recent expansion of label application.
In the tape printing device, the user can arbitrarily specify the number of lines and the character size and line-spacing for each line. With increased application range of labels, a variety of tapes with different widths and colors are set in tape cartridges. Diversity of tapes, printing lines, and printing styles makes the operation and control process undesirably complicated. When a large font is selected while the tape cartridge with a narrow tape is set in the tape printing device, or when a standard font is changed to a wider font, a print may be out of the tape width or a predetermined length. The user is thus required to manage plural types of tape cartridges with different widths and colors and check the character size and balance in the printing process.
In plural-line printing, for example, two-line printing, text data may exist only in one line. In such a case, sometimes a desirable print can not be obtained.
As described previously, in the conventional tape printing device, the character size of each line and the line-spacing are separately specified. When the text includes a large number of lines, this specification process consumes a long time period. In many cases, the user prefers a similar layout for a certain text on any width of the tape. The conventional device, however, requires specification of the character size and line spacing for every width of the tape.
The user sometimes specifies the wrong character size with respect to the tape width, which may cause an undesirable print, especially in plural-line printing.
Some improvement has been proposed in tape printing devices for printing only one line as disclosed in Japanese Utility Model Laying-Open Gazette No. 3-72461. Such an improved device detects the width of a tape set in the device and automatically determines the character size according to the tape width. This makes the user free from troublesome specification of the character size and effectively prevents printing out of the tape width.
This method is, however, not preferably applicable to tape printing devices for printing a text in plural lines. In this application, the character size is made equal for all the plural lines and the user can not obtain labels with a desirable layout including plural lines having different character sizes. Since the character size is fixed with respect to each tape width in this method, the user can not specify a desirable character size.
A text editing process conventionally applied to the tape printing device iscompletely different from that used in a word processor. While an input format and a printing format are separately determined and set in word processors, the tape printing devices have only one format. Some of tape printing devices use a format similar to the concept of the `page` used in the word processor to allow processing and printing of a text in a plurality of blocks. In such a tape printing device, part of the text exceeding a last line of a certain page is automatically input in a first line of a next page. In this manner, the user obtains a label with a long text printed thereon by repeated printing of a page unit along the length of the tape.
When a text is input and printed based on the concept of the `page`, insertion of one or plural lines in the middle of a certain page often moves the last line of the certain page to a next page. On the contrary, deletion of several lines from a certain page often causes some lines on a next page to move into the certain page. When some lines in a page are out of the tape width or when the specified character size is too large for the tape width, the lines out of the tape width are forcibly moved to a next page.
This does not cause any problem in character information processing apparatuses such as word processors but makes a serious problem in the tape printing device.
A typical text printed on a label with the tape printing device is significantly different from those printed in word processors. For example, an exemplified text includes a company logo on a left side and a company name and its address on a right side. In such a case, it is not desirable that some lines in a certain page move to a different page through deletion or insertion of one or plural lines, or that some lines in a certain page are automatically printed in a different page. The tape printing device occasionally changes an arrangement of the text printed on the label against the intention of the user. In this automatic modification system of the printing layout, the user can not recognize an exact printing layout prior to actual printing.
The tape printing device generally includes a display unit for displaying an input text. This allows the user to input a text while checking the screen of the display unit. The text is, however, typically displayed according to a predetermined character size because of the limited screen area irrespective of the character size specified by the user. Accordingly the user can not see or check a real printing image of the text.
In this device, the user checks the printing image by a trial print of an input text after completion of the whole input procedure. This method wastes an expensive tape and is thereby quite uneconomical.
A printing image display unit may be incorporated in the tape printing device to display a printing image of the input text. In the display unit, a label (tape with the text printed thereon) is typically shown as a contour as in the word processors. Display of the label as a contour requires a separate software for displaying the printing image and increases the required memory capacity, thus making the whole device bulky and expensive.
When some characters in a text are surrounded by a keyline box, the keyline is significantly close to or even overlapped with the contour of the label in a limited screen area. This prevents the user from clearly distinguishing the keyline from the contour.
Some additional functions have been proposed for easier identification of labels. For example, a proposed tape printing device has a screening function to make some characters prominent and distinct by screening. Thick screening makes target characters distinctive whereas thin screening can not sufficiently emphasize the target characters. Since labels are often seen and read from a certain distance, thin screening makes the shade unobservable.
In the a tape printing device, the user sometimes requires use of specific characters and symbols which the user independently determines and defines (hereinafter referred to as foreign characters). These foreign characters include company logos, special marks, and characters in a specific language. Since the tape printing device is generally used for preparing labels with desirable prints thereon, a foreign character registration function is essential.
A conventional method of registering a foreign character in the tape printing device is similar to that in other character information processing apparatuses as given below.
When a foreign character input mode is selected, a working dot pattern of NxN dots (for example, N=16, 24, 32, 48) is displayed in a color identical with that of a background of a display unit, where all the N.times.N dots represent background dots and the cursor is displayed on a certain dot in flickering manner. The cursor is moved according to operation of the cursor keys while the certain dot with the cursor is inversely displayed as a dot element constituting part of a foreign character according to operation of the dot-on key. After the user selects one or a plurality of dots as dot elements constituting a foreign character, the user presses the registration key to register the whole N.times.N dot pattern as a foreign character dot pattern.
In this conventional foreign character registration method, the user easily confuses the background of the working dot pattern with the background of the display unit.